1. Field of the Invention
The present invention relates to a jam-resistant tacker apparatus, and more particularly to a tacker apparatus that prevents tacker pins from becoming jammed by guiding a tacker pin and a pusher, which move within a connection area between a magazine and a magazine cover, to tightly contact the magazine without generating a gap.
2. Related Prior Art
As generally known, a tacker, a nailer, a stapler and a pinner are pneumatic machines widely used in the fields of interior and exterior construction, aluminum sash work and so on, to fasten certain materials to each other; for example, wood to wood, wood to plastic, wood to steel, or wood to concrete.
A general tacker apparatus comprises a body including therein a piston and a cylinder, a lid for supplying the piston with air and discharging the air therethrough, a magazine loaded with a nail, a staple, or a pin, a guide for guiding the trajectory of the nail, a safety device for safe operation, a fastening device for loading of the nail, a bracket firmly connecting the magazine to a handle, and a trigger assembly for operating the tacker apparatus.
In such a tacker apparatus, the piston disposed within the body is moved by operating the trigger assembly so that the nail or stapler loaded in the magazine is shot through the guide to penetrate a desired position.
FIGS. 1A and 1B are exploded perspective views illustrating the structures of the magazine and the pin guide members, respectively, constituting a conventional tacker apparatus. FIG. 2 is a plan sectional view showing the magazine of the conventional tacker apparatus, as assembled. FIG. 3 schematically shows pins being guided by the magazine of the conventional tacker apparatus. FIGS. 4A and 4B illustrate the principle of loading the magazine with the pins in the conventional tacker apparatus. FIG. 5 is a side view of a pin guide included in the magazine of the conventional tacker apparatus.
Referring to the drawings, a conventional tacker apparatus 2 includes a tacker body 4 with a piston and a cylinder mounted therein, a guide 6 disposed on the front side of the tacker body 4 to seat a staple or a pin and guide its trajectory, and a magazine 10 disposed at a lower part of the guide 6 and containing a plurality of staples or pins.
A handle (not shown) is formed on the lower part of the magazine 10. A trigger assembly 8 is formed at a predetermined position at the joint between the tacker body 4 and the handle.
Here, the magazine 10 includes a magazine body 12 to contain the staples or pins therein, and a magazine cover 18 mounted to a front side of the magazine body 12 such that it can slide in a vertical direction to allow loading of the staples or pins.
A sliding surface 14 is formed at a front side of the magazine body 12 for a tacker pin 56 to move along. At one side of the sliding surface 14, a prominent surface 16 having a high frictional resistance is attached to cope with friction generated from sliding of the magazine cover 18.
The magazine cover 18 is connected to the magazine body 12 such that it can slide in a vertical direction. The magazine cover 18 includes a cover body 20 having a plurality of grooves on the front side thereof, including: a first pusher linkage guiding groove 22 formed horizontally on one side, a first pin guide inserting groove 26, a second and third pin guide inserting groove 28, a second pusher linkage guiding groove 24, and a prominent surface inserting groove 30. Those grooves are formed in the above order all in a longitudinal direction of the magazine cover 18. Additionally, a pusher contacting surface 32 is formed on the front side of the magazine cover 18, facing the sliding surface 14.
First and second pusher linkages 36 and 38 are inserted and guided in the first pusher linkage guiding groove 22 and the second pusher linkage guiding groove 24, and equipped with connection holes 36a and 38a on the front sides thereof, respectively. A connection piece 54 of a pusher 52 is inserted into the connection holes 36a and 38a. A spring 40 is connected to a lower end of the first and second pusher linkages 36 and 38.
The pusher 52 is formed by a square metal piece and includes a connection piece 54 on a rear surface thereof. The connection piece 54 is bent perpendicular to the pusher 52 and engaged with the connection holes 36a and 38a of the first and second pusher linkages 36 and 38. Therefore, the pusher 52 is actuated by the force of the spring 40, and pushes the tacker pin 56 disposed at an upper end thereof up toward the guide 6.
First to third pin guides 42, 44 and 46 are inserted correspondingly in the first pin guide inserting groove 26 and the second and third pin guide inserting groove 28. In order to securely fix the first to third pin guides 42, 44 and 46, which are made of a thin metal plate, into the first pin guide inserting groove 26 and the second and third pin guide inserting groove 28, a plurality of spacers 48 are attached to the flanks of the first to third pin guides 42, 44 and 46.
The tacker pin 56 of the pusher 52 moves through a gap A formed in a connection area between the magazine 10 and the magazine cover 18. Therefore, the first to third pin guides 42, 44 and 46 are configured so that the pusher 52 is capable of efficiently pushing up the tacker pin 56, by optimally maintaining the gap A.
In addition, pin connection holes are formed at upper and lower ends of the first to third pin guides 42, 44 and 46. An upper pin 34 and a lower pin 50 are connected respectively through the upper and lower pin connection holes, thereby fixing the first to third pin guides 42, 44 and 46 to the magazine cover 18.
In the magazine 10 of the conventional tacker apparatus 2, if the first to third pin guides 42, 44 and 46 connected to the magazine cover 18 protrude too much toward the magazine 10, the tacker pin 56 and the pusher 52 become jammed and unable to move through the gap A between the magazine 10 and the magazine cover 18. Therefore, the first to third pin guides 42, 44 and 46 are configured not to protrude by more than a certain length from the magazine cover 18.
However, when the gap A between the magazine 10 and the magazine cover 18 is formed to exceed a proper size for the above reason, a jam between a tacker pin group 56a and another tacker pin group 56b may be induced.
More specifically, the tacker pins 56 used in the tacker apparatus 2 are supplied in the form of a tacker pin group formed by engraving uneven lines on a metal piece. Generally, in the same manner as staples, the tacker pins 56 are cut by group and loaded into the magazine 10. However, although the tacker pin group 56a disposed at an upper part is supported by the tacker pin group 56b disposed at a lower part as shown in FIGS. 4A and 4B, the upper and lower tacker pin groups 56a and 56b are apt to jam against each other because the gap A of the conventional tacker apparatus 2 is excessively large compared to the thickness of the tacker pin 56 and the pusher 52.
Especially in the case where the tacker pin groups 56a and 56b are moved to the upper end of the magazine 10 by the pusher 52, when a striking blade 60 moving horizontally to the guide 6 strikes the rear end of the upper tacker pin group 56a, the striking force is focused on the rear end. Therefore, the front side of the upper tacker pin group 56a is bent downward by a predetermined angle, thereby often generating a jam with the lower tacker pin group 56b. 
The first to third pin guides 42, 44 and 46 mounted to the magazine 10 of the conventional tacker apparatus 2 are in tight contact with the magazine body 12, keeping a small gap with the magazine body 12 so as to be pushed smoothly upward by the pusher 52. However, when the upper front ends of the first to third pin guides 42, 44 and 46 are vertically formed, the last tacker pin 56 cannot correctly reach a striking position.
Accordingly, in order to shoot the last individual tacker pin 56, a corner-R processing (b) should be performed on the upper front ends of the first to third pin guides 42, 44 and 46.